Prolonged block with recovery after extradural analgesia for labour

A patient had a prolonged block after continuous extradural analgesia in labour. The block was unilateral, but 60 min after a second block there was bilateral sensory and motor loss. The original unblocked side did not recover fully until more than 60 hr. The local anaesthetic agent was 18 ml of bupivacine 0.5% plain.